Thursday 28 September 2017

Mapping Mountains – Hill Reclassifications – Humps


Coed y Cefn (SN 950 682) – Subhump addition

This is the fifteenth in a series of Hill Reclassification posts that detail hills whose status has been altered in the listing of the Humps (HUndred Metre Prominences) through map study and / or surveys that I have conducted.

Coed y Cefn (SN 950 682)

The hill name used in this and forthcoming posts is that used in the listing of Humps, therefore individual names and their composition may not match those that are used in listings I am directly associated with.  However, I am of firm belief that listed hill names used by other authors should be respected when giving detail within other people’s lists, however inappropriate some hill names may be considered.

This and forthcoming posts are retrospective as many of these hill reclassifications were initiated from studying the Ordnance Survey enlarged mapping that is hosted on the Geograph website, and for the reclassifications that affected the Humps the email I posted on the RHB Yahoo Group forum in relation to this hill was dated 12.06.13.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for the reclassification appear below:

There has been an addition to the listing of the Humps (HUndred Metre Prominences) due to consulting the Ordnance Survey enlarged mapping that is hosted on the Geograph website, with these details being posted on the RHB Yahoo Group forum on 12.06.13.

Prior to this notification Mark Jackson had listed this hill with c 89m of drop based on a c 341m estimated summit height and a bwlch height of 252m taken from the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.  However, the Ordnance Survey enlarged mapping hosted on the Geograph website gives this hill a 342m summit spot height and when coupled with its 252m bwlch spot height it gives this hill 90m of drop, which is sufficient for it to be classified as a Subhump.

Extract from the Ordnance Survey enlarged mapping hosted on the Geograph website showing the 342m summit and 252m bwlch spot heights

The hill appeared under the name of Ochr-cefn in the Tumps prior to this notification, with this name having appeared in the 300m Welsh P30 list published on Geoff Crowder’s v-g.me website and which was derived from buildings situated to the west of the hill’s summit.  When this notification was posted on the RHB Yahoo Group forum brief details relating to the hill’s name were included, due to this post the name of the hill now appears as Coed y Cefn.

The hill is adjoined to the Elenydd group of hills and is situated overlooking the A 470 road, the Afon Gwy (River Wye) and the town of Rhaeadr Gwy (Rhayader) which are all towards the east of the hill.

The addition of this hill to Subhump status was accepted by Mark Jackson and the listing of the Humps was updated accordingly.

Coed y Cefn was subsequently surveyed with a Trimble GeoXH 6000 on the 14.04.15, resulting in this hill having a 342.2m (converted to OSGM15) summit height and a 251.3m (converted to OSGM15) bwlch height, with these values giving this hill 90.8m of drop.


Gathering data with the Trimble GeoXH 6000 at the summit of Coed y Cefn


The full details for the hill are:


Name:  Coed y Cefn

Summit Height:  342.1m (as listed in the Humps, 342.2m converted to OSGM15)

OS 1:50,000 map:  136, 147

OS 1:25,000 map:  200

Summit Grid Reference:  SN 95081 68222 (as listed in the Humps)

Drop:  90.8m (converted to OSGM15)



Myrddyn Phillips (September 2017)

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